The Tektronix R7903 is a rackmount version of the 7904. It takes only one horizontal plug-in. Otherwise, aside from being rackmount shape, it the same as a 7904.
|Fastest calibrated sweep||500 ps/Div (with 7B92A, other time bases "uncalibrated for first 60 ns")|
|Acceleration voltage||24 kV|